copy Properties from Java Bean

Description

Demo Code


import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Main{
    public static void main(String[] argv) throws Exception{
        Object target = "java2s.com";
        Object source = "java2s.com";
        copyProperties(target,source);//  ww w .j a va2  s . co m
    }
    public static void copyProperties(Object target, Object source) {
        copyProperties(target, source, null);
    }
    public static void copyProperties(Object target, Object source,
            String[] ignoreProperties) {
        if (target instanceof Map) {
            throw new UnsupportedOperationException(
                    "target is Map unsuported");
        }

        PropertyDescriptor[] targetPds = getPropertyDescriptors(target
                .getClass());
        List ignoreList = (ignoreProperties != null) ? Arrays
                .asList(ignoreProperties) : null;

        for (int i = 0; i < targetPds.length; i++) {
            PropertyDescriptor targetPd = targetPds[i];
            if (targetPd.getWriteMethod() != null
                    && (ignoreProperties == null || (!ignoreList
                            .contains(targetPd.getName())))) {
                try {
                    if (source instanceof Map) {
                        Map map = (Map) source;
                        if (map.containsKey(targetPd.getName())) {
                            Object value = map.get(targetPd.getName());
                            setProperty(target, targetPd, value);
                        }
                    } else {
                        PropertyDescriptor sourcePd = getPropertyDescriptors(
                                source.getClass(), targetPd.getName());
                        if (sourcePd != null
                                && sourcePd.getReadMethod() != null) {
                            Object value = getProperty(source, sourcePd);
                            setProperty(target, targetPd, value);
                        }
                    }
                } catch (Throwable ex) {
                    throw new IllegalArgumentException(
                            "Could not copy properties on:"
                                    + targetPd.getDisplayName(), ex);
                }
            }
        }
    }
    public static PropertyDescriptor[] getPropertyDescriptors(
            Class beanClass) {
        BeanInfo beanInfo = null;
        try {
            beanInfo = Introspector.getBeanInfo(beanClass);
        } catch (IntrospectionException e) {
            return (new PropertyDescriptor[0]);
        }
        PropertyDescriptor[] descriptors = beanInfo
                .getPropertyDescriptors();
        if (descriptors == null) {
            descriptors = new PropertyDescriptor[0];
        }
        return descriptors;
    }
    public static PropertyDescriptor getPropertyDescriptors(
            Class beanClass, String name) {
        for (PropertyDescriptor pd : getPropertyDescriptors(beanClass)) {
            if (pd.getName().equals(name)) {
                return pd;
            }
        }
        return null;
    }
    private static void setProperty(Object target,
            PropertyDescriptor targetPd, Object value)
            throws IllegalAccessException, InvocationTargetException {
        Method writeMethod = targetPd.getWriteMethod();
        if (!Modifier.isPublic(writeMethod.getDeclaringClass()
                .getModifiers())) {
            writeMethod.setAccessible(true);
        }
        writeMethod.invoke(
                target,
                new Object[] { convert(value,
                        writeMethod.getParameterTypes()[0]) });
    }
    private static Object getProperty(Object source,
            PropertyDescriptor sourcePd) throws IllegalAccessException,
            InvocationTargetException {
        Method readMethod = sourcePd.getReadMethod();
        if (!Modifier.isPublic(readMethod.getDeclaringClass()
                .getModifiers())) {
            readMethod.setAccessible(true);
        }
        Object value = readMethod.invoke(source, new Object[0]);
        return value;
    }
    private static Object convert(Object value, Class<?> targetType) {
        if (value == null)
            return null;
        if (targetType == String.class) {
            return value.toString();
        } else {
            return convert(value.toString(), targetType);
        }
    }
    private static Object convert(String value, Class<?> targetType) {
        if (targetType == Byte.class || targetType == byte.class) {
            return new Byte(value);
        }
        if (targetType == Short.class || targetType == short.class) {
            return new Short(value);
        }
        if (targetType == Integer.class || targetType == int.class) {
            return new Integer(value);
        }
        if (targetType == Long.class || targetType == long.class) {
            return new Long(value);
        }
        if (targetType == Float.class || targetType == float.class) {
            return new Float(value);
        }
        if (targetType == Double.class || targetType == double.class) {
            return new Double(value);
        }
        if (targetType == BigDecimal.class) {
            return new BigDecimal(value);
        }
        if (targetType == BigInteger.class) {
            return BigInteger.valueOf(Long.parseLong(value));
        }
        if (targetType == Boolean.class || targetType == boolean.class) {
            return new Boolean(value);
        }
        if (targetType == boolean.class) {
            return new Boolean(value);
        }
        if (targetType == char.class) {
            return value.charAt(0);
        }
        if (DateHelper.isDateType(targetType)) {
            return DateHelper.parseDate(value, targetType, "yyyyMMdd",
                    "yyyy-MM-dd", "yyyyMMddHHmmSS", "yyyy-MM-dd HH:mm:ss",
                    "HH:mm:ss");
        }

        throw new IllegalArgumentException("cannot convert value:" + value
                + " to targetType:" + targetType);
    }
}
copy Properties from Java Bean - Java Reflection

Description

Demo Code

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